Fire control apparatus for guns



June 28, 1949. M. K. INGOLDBY 2,474,739

- FIRE CONTROL APPARATUS FOR GUNS v Filed Feb. 2'7, 1945 5 Sheets-Sheet 1 3mm ,W

June 28, 1949. INGOLDBY 2,474,739

FIRE CONTROL APPARATUS FOR GUNS Filed Feb. 27, 1945 5 Sheets-Sheet 2 swam WWW, @ecmaab.

Gimme/g Patented June 28, 1949 UNITED STATES 2,474,739 FIRE CONTROL APPARATUS FOR GUNS Maurice Kerr Ingoldby, deceased, late of Tynemouth, England, by Thomas Frederick Clarke,

Swanley, England, and Percy William Cole,

Purley, England, executors, assignors to Vickers-Armstrongs Limited, London,

England, a

company of Great Britain Application February 27, 1945, Serial No. 580,031 In Great Britain October 12, 1937 Section 1, Public Law 690, August 8, 1946 Patent expires October 12, 1958 11 Claims. 1

This invention relates to a fire or like control apparatus for guns, torpedo-tubes, or similarly controllable devices and is concerned with control apparatus taking into account those relative movements between the gun or the like and the target. Fonsimplicity of language herein use is made of terms such as guns, gun transmission, fire control apparatus. Although all these terms have a primary application to guns only they are to be considered, if the context permits, as including apparatus where an analogous problem of control arises as, for example, in torpedo discharging gear.

In known prediction apparatus employed for the calculation of adjustments to be imparted to a gun mounting, a sight is employed for following the target, the movements in training and elevation which it is necessary to apply to the sight in order that it should follow the target being communicated to the predictor where such movements are analysed to obtain gun deflections. The analysis of the sight movements which takes place in the predictor must include the determination of the rate of change of the sight movements when the sight is following the target. This may be achieved with the aid of the wellknown balance dial constrctions, or alternatively, an indicating instrument might be used. An indicating instrument would have the disadvantage that little power would be available for operation of the prediction apparatus, whilst the employment of balance dials necessitates an observer or observers to work at the predictor maintaining the coincidence of the pointers and dials.

It is the aim of the present invention to provide apparatus which will satisfactorily operate in the determination of rates of change of sight elevation and training with the employment of as few observers as possible, so that the fire control apparatus may be mounted upon or within an aeroplane. Following this general requirement it will, of course, be desired to eliminate personnel from the associated gun (or guns), the latter being trained and. elevated in a fully automatic fashion. Known gun control apparatus will, in general, either operate with great accuracy but low power or with power suflicient to operate the gun mounting with but a relatively low accuracy. It will, of course, be appreciated that the object of the invention in producing automaticity with great accuracy in the prediction and sighting portion of the control apparatus will be completely defeated if the gun transmission does not also operate with complete automaticity and extreme precision.

According to the invention, a fire control system includes an observing sight, a predictor or calculator and gun operating mechanism wherein the movements of the sight in training and elevation are controlled through hydraulic swash-plate pump and motor systems, each such system possessing control means to vary the volume of the supply of the fiuid medium with the aid of a valve or by varying the angulation in the swashplate system, and wherein there are connections from the training and elevating mechanism of the sight to the predictor or calculator so as to introduce into the latter, movements corresponding to the actual training and elevating movements 5 of the sight, there being further connections from said control means to the predictor or calculator so as to introduce also into the latter movements that are proportional to the rate of change of the sight elevating and training adjustments.

According to a further feature of the invention,

the output from the calculator or predictor, consisting of corrections in training and elevation to be applied to the associated gun, is magnified by a power amplifier hunter follow-up system comprising a swash-plate hydraulic system with hunter gear.

It may here be mentioned that in previously proposed fire control systems, it is known to employ a sight operating in conjunction with a gun,

- the elevating and training movements of which are controlled by the motors of hydraulic pump and motor systems. Each pump has a control member which is movable to govern the rate of operation of the associated motor and is, therefore, in its movements proportional to such rate.

The sight is carried by the gun and the time of flight is combined with the measured rate just indicated and applied back to the sight to deflect the latter in such manner that the gun should be 49 laid in advance upon a predicted position of a moving target. It may also be mentioned that hydraulic swash-plate systems for remote operation of a gun mounting are known per se.

In order that the said invention may be clearly 4,5 understood and readily carried into effect, the

same will now be more fully described with reference to the accompanying drawings, in which- Figure 1 is a diagrammatic view of a fire control system according to the invention.

50 Figure 2 is a sectional view of a detail of the apparatus employed.

Figure 3 is a view similar to Figure 1 of a modified system, and

Figures 4 and 5 are details of the apparatus employed in the system of Figure 3.

Referring now to the drawings, and in particular to Figure'l thereof, there is an optical pipes are supplied from hydraulic swash-plate pumps 9 and I which are; in mm, respectively driven from sources of mechanical powerindicated at I I and I2. The angulation of the swashplates of both the pumps 9 andW O is controllable by means of arms I3 and I4. Each arm is effectively attached to a nut device I5 and IS, the latter working on worm-screws IT and I8; The worm-screws are respectively carried by shafts I9 and 20, each of which is provided with acontrolling handwheel 2i and 22.

Associated with the apparatus so far described there is a calculator or predictor 23 which is intended to derive future corrections for an associated gun (or guns) with the aid of certain given present values. Amongst the desired present values there will be the training and elevating displacements made to the sighting device I. Measurements of these displacements are obtained from the shafts 3 and A with the aid of bevel pinions 23A and 24 associated with shafts 25 and 26. The shaft 25 experiences a movement according to the training adjustment whilst the shaft 26 experiences a movement according to elevation adjustment. There is additionally required for the calculator 23 an accurate estimationtof the rate of change of both training and elevation. For reasons that will be indicated more fully hereinafter, a. measure of the rate of change of training is obtained upon a shaft 2'! that is connected with the shaft I19 through a bevel pinion pair 28. There is also a shaft 29 which connects with the shaft ZIJ through the bevel pair 30, the shaft 29 affording a measure of rate of elevating. The sighting device i is equipped with the usual range-adjusting handwheel 3I and appropriate mechanism 32 from which there is a connection 33 to the calculator or predictor 23 for the purpose of setting therein the present range.

From the predictor or calculator 23 there emergetwo shafts 34 and 35 and, since the mechanism associated with each shaft is exactly simifar, it will mice to describe only one of such mechanism. The shaft 35, through gears 36 and 31 drives a shaft3'8. The latter possesses a non-round part 33 and the gear 31 is slidable thereon having an extended boss 40 which, by means of a bearing MA, holds the gear 31 in fixed relation to the gear 36 when the shaft 38 is axially displaced. There is a bell-crank ll arranged at one end to co-operate with a collar 42 supported fixedly on the shaft 38 and arranged to have its other extremity connected by means of a rod 43' with an arm 44, the adjust ment of which governs the angulation in a hydraulic swash-plate pump 45. The latter is associated with a swash-plate motor 46, and there is a source of mechanical energy 41 for actuating the pump 45. An output shaft 48 receives the drive from the motor 46 and there is a gearwheel 49 secured upon such shaft. The gearwheel 49 meshes with a gearwheel 56 having an internally screw-threaded boss 5|, which engages with external screw-threading 52 upon the 4. shaft 38. The boss 5| has an integral extension carrying a gearwheel 53, whilst'the-shaft 38 has a non-circular section portion 5 supporting a further gearwheel 55, so that the latter may remain in a relatively stationary position along the axially movable shaft 38. There is means in the form of a bearing boss I51] for maintaining the gearwheel at a fixed location so that if such gearwheel were rotated without there being any rotation of the shaft 38, the latter would be moved axially by virtue of the screw-threading upon the interior of the gearwheel boss 5| and the exterior of the shaft 38. A casing 55 is disposed for angular movement about the shaft 38 I and carries a shaft 5? to which there is fixed a pair of pinions 58 which mesh with the gearwheels 53 and 55. A series of teeth indicated at 59' is disposed around the periphery of the casing' 58, such teeth being intended to engage with a pinion Ell located on a shaft 6| that returns to the calculator or predictor 23.

The shaft 48 is mechanically connected with a shaft 62 entering a gun-adjusting mechanism 63. The shaft 34 is associated with mechanism precisely similar to that already described and there is an output shaft .64 which likewise enters the gun-adjusting mechanism. 63. There is also a return shaft 55' which enters thepredictor or calculator 23.

In Figure 2 there is shown, in section, mechanism for elevating and training either the sight I or the gun to which themechanism is to be applied. Thus, the sectional view in Figure 2 maybe regarded as a detail of'the mechanism 2 or 63. In Figure 2 it will-be seen that there is a main central shaft 66 which effects the training adjustment, there being a gearwheel 51 attached to the shaft and meshing with a control worm 58. There is a similar control worm 69 meshing with a toothed annulus 70 which engages with the pinions H of an epicyclic gear. A drive from the pinions II is taken upon a sleeve 12 which is formed integral with a gearwheel l3, meshing with a further gearwheel M which in turn serves to drive a shaft for effecting elevati-on adjustments. It will be unnecessary to describe the construction of the epicyclic gear in detail and it will suffice to state that there is also a rotatable cage '56 with further planet pinions ll meshing with a gearwheel 78 upon the shaft 66 and also meshing with a toothed portion 79 on the housing of the mechanism. The epicyclic action permits elevation adjustment of the shaft 15 without disturbance or variation by the training adjustments.

Referring now once more to Figure 1 it will be seen that the shaft 66 of Figure 2 may be regarded as equivalent to the shaft indicated at 80 in connection with the range-finding device I, whilst the shaft 8! may be regarded as equivalent to the shaft I5. In a similar manner in connection with the gun-adjusting mechanism 63, the shafts 82 and 83 thereof may respectively correspond to the shafts 66 and 15 ofthe mechanism of Figure 2.

In the use of the apparatus so far described, it will be understood that the range-finding and sighting device I will be controlled by visual observation. The observer will be able to adjust the range-finder in elevation and training by means of the handwheels 22 and 2I'. The range will be set by the handwheel 3! and will be transmitted to the calculator 23. Byadjustment of, say, the handwheel 22 it will be understood that a directly proportional movement will be given to the lever I4 which determines the swash-plate angulation in the hydraulic pump I0. Moreover, movement of the lever I4 is proportional to the speed at which the hydraulic motor 9 will run, given a constant speed for the source of mechanical power I2. If, therefore, the handwheel 22 is being operated so that the shaft 4 keeps the observing sight, 1. e., the rangeflnder, correctly adjusted in elevation upon the target, then it will be seen that the handwheel 22 is moving in accordance with rate of change of elevation. Such rate of change of elevation is set upon the shaft 29 and into the calculator 23. For obvious reasons, the shaft 26 will move in accordance with the actual elevation adjustment, and for like reasons the shaft 21 will move according to rate of change of training whilst the shaft will move according to actual extent of training. The calculator or predictor 23 deals with these inputs and forms no part of the present invention. Furthermore, the calculator '23 may have other inputs so that there may be derived finally therefrom, gun adjustments in trainin and elevation upon the output shafts 34 and 35. The mechanism for obtaining power followup from the shafts 34 and 35 is identical and only that associated with the shaft 55 need be described. In operation this mechanism functions as a power amplifier with hunter follow-up. When the shaft 35 turns, the movement thereof is communicated to shaft 35 through the gearwheel 3! and due to the threading 52 on the shaft 38 the latter is moved axially. The axial movement produces a swinging of the bell-crank lever 4| which, in turn, adjusts the angulation of the swash-plate in the hydraulic pump by means of the lever 44. On a given. adjustment of the lever 44 the motor 45 is set in motion, and there is a drive back from the gear 49 to the gear 50 whereby the screw-threading of the boss 5| carries back, or tends to carry back, the shaft 38 axially towards the position thereof corresponding to a zero setting of the bell-crank lever 4|. In a hunter system such as that just described, there will be a certain lag and a correction must be made therefor. For this purpose the shaft 6| is arranged to move in accordance With the extent of lag anddrives back into the calculator 23. The movement of the shaft 6| is, at all times. proportional to lag in the hydraulic system for the following reasons. The gearwheel 53 can move only at the same speed as the gear 50 which, in turn, moves according to the speed of the output shaft 40 from the motor 46. On the other hand, the gearwheel 55 must move with the shaft 38. Thus, if the shaft 35 were displaced and, as a result, the shaft 38 similarly displaced, then there would be a lag before rotation of the gear 49 begins and during the period of that lag the gearwheel 55 would be driven Whilst the gearwheel 53 would remain stationary. Since both the pinions 50 are fixed upon the shaft 51, the casing 56 must rotate and transmit rotary motion to the shaft 0|, proportional to the extent of lag between the input control and output power sides of the hydraulic system.

Referring now to the system shown in Figures 3, 4 and 5, it will be seen that there is in this case also a similar arrangement of a range-finder or sighting device 84 having a control mechanism 85 as shown in Figure 2 of the drawings. As in the previous example, there is an elevation adjusting shaft 86 and a training adjusting shaft 81, both of which communicate with the calculator 88 by means of shafts 89 and 90. There are hydraulic swash-plate motors 9| and 92 associated With the shafts 86 and 81 respectively, and there are control handwheels 93 and 94 also associated therewith. In this example, however, the motors 9| and 92 are supplied with pressure fluid from a common pump 95 which receives mechanical energy from the power source 96. There are two pipes 91 and 98 from the pump 95, 99 representing the pressure side and 91 the return. The pipe 91 extends to a T-portion 99, from whence fluid medium is fed back to the pump 95 from valve boxes I00 and II. Fluid medium is fed from the pipe 98 to the valve boxes by the branch pipes I02 and I03. From each valve box I00, IllI, there is a pair of pipes I04, I05 which extends to its associated motor 92, 9| respectively.

In Figure 5 there is shown a detail of a valve box such as indicated at I00 and IOI in Figure 3. The box includes essentially a body member I06 and a valve stem I01 in the extremity of which there is engaged the end of a centrally pivoted lever I08. The other end of such lever is effectively attached to a nut I99 adapted to cooperate with a threaded member III] upon the shaft III. There is a hand-wheel upon the shaft so that by the rotation of the latter the valve stem I0'I may be made to move axially in either direction.

The valve box body I06 has ports IIIBA, corresponding to the pipes I04 and I05 and furthermore has a fluid medium inlet I 09A and outlet 9A, which may be connected respectively to the pipes I02 and 99, for example. There is a main interior valve chamber II2 which, in this instance, may be of cylindrical form and there is a passageway ||3 communicating at either end with the chamber I I2 and opening into the outlet IIIlA. A reversing valve is employed in the chamber H2, the valve possessing portions H4 and H5 which fit within the chamber H2 and which are capable of closing almost completely the ports I08A. From the arrangement of the valve illustrated it will be appreciated that if the valve is moved from the zero central setting in either direction, then depending upon the direction of movement the fluid medium will flow into the inlet I09A and out of one or the other of the ports I08A. That port I USA which does not connect with the inlet I09A, then functions as the exhaust port and permits return fluid medium to pass through the channel '3 to the outlet IIIJA, thence back to the return side of the central pump of the system. It is important to note that in the valve described the design has to be such that the extent of opening of the valve, by movement of the controlling handwheel, is proportional to the resulting volume of fluid from the outlet side of the valve box, through either'of the ports IIlilA. It is, furthermore, desirable that when the valve is in its zero position, pressure fluid may escape through both the ports I05A to some slight extent in order that the associated motor might be held firmly in a zero position.

Returning now to Figure 3 of the drawings, it will be seen that the handwheel 94 associated with the valve box I00 has a control shaft H6, and that the corresponding handwheel 93 of the valve box I0| has a control shaft II'I. Both the shafts I I6 and I I1 enter the calculator or predictor 88. From the predictor there are emergent shafts I I8 and I I9 which have set upon them corrections for gun elevation and training. Such corrections are amplified through a power ampagans npli-fier, and II'LHI-ItEIZvfOHOVIqJ- P system 'and applied min alglun control-V,mechanismHIZELt hich maybe "tithe same as that,alreadyindicated in theprevisous, construction. ;:.T he ;power. amplifier system Nasscciatedmvith aeach,,correction isv identical, and itisuflicesa. thereforento .zdescr-ibea-one in detail. The output-shaftil w is connected by gearing I2I nivith a shaft; I22 which enterslag correction-and shunting? gear. I23. H There is :an-output; shaft .124 from the latter. which v drives back, through gearng ,125; into the ,calculator. 88. The shaft I24 is arranged to have: a.-movementproportional-:to ,,,the ,lag inthe power-amplifier. There is a hydraulic swash-plate,motor. I-25A. having an out- ,nput shaftl-Zfiwhich entersgun control vgeargl2ll.

..FigL1re etmaytbegregarded as a detail of the .,power amplifier; system just briefly described and it will be.,seen that the,,motor I 25A ghas pipe connections I2! and I28 to a valvesbox.I29 (assumedinfli'igure 3 to beenclosed in, the casing L23,..for simplicity. ot'drawing). It. will beHseen' w-thati-the construction ofwther .valve box [29 is ,esimilar tohthatshownin- Figure 5, except that a the zvalvestemhlw has a.yoke end which supports a-.camfollower.,|3l. ,There. is, as before, a fluid .nmedium ,inletMI32 which is intended, to be connested-to,the pipe.il33.,,(see Figure 3). Thereis likewisetan ,outletil 34cforithe fluid medium which i. is intended to beconnected. tothe pipeTI3 5. From Figure 4..it,willnberseenuthat the,.,shaft I22 has .isecuredito itargearwheel J36 which meshes with a,,.pinion,.l3'lssecurediupon a shaft I38 carryi ingl a furt,he1n fixed pinion .I39. 'Ihe latterengages. with. a. ,gearwheel Mil securedv upon the extension 14L of.v .the .output shaft I26 of the hydraulic motor,. I25A. .There is aucasing I42 whichiserves,toicarrytheshaft J33 and which a is itself.,angularlyu,displaceable, about the axis of. the shafts..gl22..,and.,l4l. .,The..casingi I42 is Mformedwith. a cam M3 which, is so profiled that the lift .experienced.. by. the follower. I3l is proportional toithe angular distanceth-rough which lithe, cam may. be turned. There is alsopro- ..vided..upon tl1e,,ca$ing aperipheral series of eigearteeth. I44 which .meshwith a pinion I45 secured to the. shaft I24.

From,the,above,.description. it, will be under- .stoodthat, if. the shaft A22. is ,turned (with the Wmotor, I25A,.initially., inoperative) vthen. the cas- ..,ing ,IAZ-will be angularly-displaced by. virtue ,of -,.the,pinions.,.I3'I andiI39. Thereby..the cam .I43 will cause a proportionatedift of the, follower Il3I sandnuid medium, will flow in,one direction or the nether. to .the hydraulic. motor, -wher.eupon ,thelatter will beginto operate accordingly. The extension A I 4 I oft the .outputshaftd 2 B will thereby,be rotated.so thatthespinion M0 will like- ,;wise rotatevandatendfl to returnwtheyalve. I29 to vits zero position by..virtue of the cam-follower arrangement. i It willibeseen that the movement 60 .of! the .casing ..I 42 willabe a direct 'measure of, the slag in the hydraulic system and that the shaft .,.;,I 2 4. will turns-in 1 accordance with. such lag.

* The-power amplifier hunter follow-up system described is in thismparticular instance, applied :.:t0 training. It will, be-understood that a-precisely similar system is applied to the elevating --1correction.

- The operation of the system as a whole is simialar' to thateotthesystem illustrated in Figure 1, 7 the movements of the shafts H6 and I I! being, ,..in thiscase-proportionalto the rates of train- ,-,ing and elevatingrrespectively since the adjustrments made in .thewvalve-boxes I00 and IIII will ,,,control the. rate, of -operation; of the v respective s8 hydraulie motors-9 I and 92. whichdirectly-con- Y. -trol theveleva'tingand training, mechanism. I The system of Figure 3--will-;be:observed to have .certain advantages over that-described. with reference to: Figure 1,: for the ,reason that asingle sourcepf ,fiuid-- medium,,indicated at 95 is- -all that is .necessary to operate the various hydrauu lichmotors. In the; previously. described ;system each, hydraulic unit is complete with pump and v motor.

In the above described systems thevuse of two -...,controlz handles.haslbeenreferred to, one inrespectof trainingiand the other ion elevating. It s will be understood. that a; single universally ad- '15,.dustable-memberi such. as a ..,joy-stick control member s may: be utilised.

What isclaimed is:

1...In a...firecontrol,system,..sighting means, a H predictor, input andoutput motion transmitting imembers associated, with said predictor, lgunuopcrating "mechanisms controlled by ,the output members of the. predictor, hydraulic. motors having output connectionstosaid sighting means for imparting. training, and elevating movementsto 25. the. sighting means and alsoihaving driving .con-

,nections to the. input members of the predictor so as to applyto the predictor measurementslof training and elevating displacements. ofthe sightins means, hydraulic ,fluidhpressuregenerating means supplying said. motors means regulating the supply of hydraulic.fluidtpressureto said hydraulic ,motors for. selectively controlling the adjustment of, the sighting means .for training. and elevation, and meanstransmitting tolthe predictor a measure of the rateuof trainingandelevation applied to said regulating means.

2. In a fire, control,system, sighting means, a predictor, input and outputamotion transmitting ,.,members associated with said predictor; gun-op- 40. ieratingmechanism, hydraulic motors having output connectionsv tosaid. sighting means for :im- ,fparting trainingand elevating movements to the lsightingimeans and. also having driving connec- ,tions to the input-members of theipredictor so as torapply to thepredictormeasurements of train- .ing and elevating displacements of the sighting a :means, pu-mps. supplying the said hydraulic mo- .tors, means for selectively adjusting said pumps i to control theadjustment of the sighting means for training and-elevation, and means transmitting to the :predictor a measure of the rateof trainingv andelevation appliedtothe sighting mmeans via: said adjustable pumps, the output members driven fromthe-said-predictor being i-adapted toapply corrections in training and ele- .hvationl to .the gun operating 'm-echanism.

, 3.-Ina fire cont-rol system, an observingsight, a predicton'gun elevating and training means; a i hydraulicswash-plate motor having an output to :said sight for .ad-J'ustingthe sight in training, a.-second swash-plate motor having anoutput for adjusting thesight in elevation means trans- ,mittingsaid -training and "elevating adjustments 6 .,.of. the. sight to thepredictor, swash-plate pumps supplying hydraulic pressure fluid to said motors, ,nmeans for adjusting. theangulation in said swashplate pumps, means transmitting-to thepredictor movements proportional 1 tot -the rate of :change a 0 0f the sight elevating.andrtraining adjustments derived from the adjustment of the angulationv of risaid pumps, a hydraulic ,poweramplifier-hunter W'folloWmp system fordriving'thegun elevating W :and training means; and outputs from the pres;a-:tdictor-to=lsaid power-amplifier system ,for introducing thereto the corrections in training'and elevation to be applied to the gun.

4. In a fire control system, an observing sight, a predictor, gun elevating and training means, a hydraulic swash-plate motor having an output to said sight for adjusting the sight in training, a second swash-plate motor having an output for adjusting the sight in elevation, means transmitting said training and elevating adjustments of the sight to the predictor, a pump to supply said motors with hydraulic pressure fiuid, selectively adjustable valves for controlling the supply of hydraulic pressure fluid to said motors, means transmitting to the predictor movements proportional to the rate of change of the elevating and training adjustments derived from the adjustment of said valves, a power amplifier hunter follow-up system for driving the gun elevating and training means, and outputs from the predictor to said power amplifier system for introducing thereto the corrections in training and elevation to be applied to the gun.

In a fire control system, sighting means, a predictor, gun operating mechanism, outputs from said predictor for transmitting corrections in training and elevation to be applied to the gun operating mechanism, a power amplifier followup gear for magnifying the said corrections derived from the predictor and for applying them to the gun operating mechanism, a swash-plate pump and motor system and associated power source means for driving the pumping means of said system, means associated with the motor portion of said system for applying to the sighting means adjustments in training and elevation and for transmitting corresponding adjustments to the predictor and means for transmitting to the predictor movements proportional to the rate of change of the elevating and training adjustments of the sighting means.

6. In a fire control system, sighting means, a predictor, gun operating mechanism, outputs from said predictor for transmitting corrections in training and elevation to be applied to the gun operating mechanism, a power amplifier followup gear for magnifying the said corrections derived from the predictor and for applying them to the gear, a swash-plate pump and motor system and associated power source means for driving the pumping means of said system, means associated with the motor portion of said system for applying to the sighting means adjustments in training and elevation and for transmitting corresponding adjustments to the predictor, means for transmitting to the predictor movements proportional to the rate of change of the elevating and training adjustments of the sighting means, and a return drive from the power amplifier follow-up gear to the predictor for returning to the predictor compensation for lag in the said gear.

:1. In a fire control system, sighting means, a predictor, gun operating mechanism, outputs from said predictor for transmitting corrections in training and elevation to be applied to the gun operating mechanism, a power amplifier followup gear for magnifying the said corrections derived from the predictor and for applying them to the gun operating mechanism, a swash-plate pump and motor system and associated power source means for driving the pumping means of said system, means associated with the motor portion of said system for applying to the sighting means adjustments in training and elevation and for transmitting corresponding adjustments to the predictor, means for transmitting to the'pre dictor movements proportional to the rate of change of the elevating and training adjustments of the sighting means, and means for determining lag correction in the follow-up gear consisting of a member arranged to move with the sensitive input to said gear, a second member arranged to move with the power output from the gear and a connecting mechanism between members, said connecting mechanism being constructed and arranged that when said members run in the same direction at the same speed the connecting mechanism has no output while a difference in movement of said members produces a corresponding output from said connecting mechanism whereby the lag of said gear is determined.

8. In a fire control system, sighting means, a predictor, gun operating mechanism, outputs from said predictor for transmitting corrections in training and elevation to be applied to the gun operating mechanism, a power amplifier followup gear for magnifying the said corrections derived from the predictor and for applying them to the gun operating mechanism, a hydraulic system having swash-plate pump means and a plurality' of hydraulic motor means, associated power source means for driving said pump means, means associated with certain of said hydraulic motor means for applying to the sighting means adjustments in training and elevation and for transmitting corresponding adjustments to the predictor, said adjustment applying means embodying a pair of selectively operable manually controlled valves for controlling the supply of pressure fluid to said last named motor means, and means for transmitting to the predictor movements proportional to the rate of change of adjustment of said valves.

9. In a fire control system, sighting means, a predictor, gun elevating and training means, a pair of swash-plate hydraulic motors each having an output to the sighting means for adjusting the sighting means for training and elevation, a pump common to said motors, a power unit driving said pump, a pair of manually controlled valves for regulating the supply of pressure fiuid to said motors, connections from said valves to said predictor for transmitting to the predictor movements proportional to the rate of change of the valve positions, means transmitting the training and elevating adjustments of the sighting means to said predictor, a power amplifier hunter follow-up system for driving the gun elevating and training means, and outputs from the predictor to said power amplifier system for introducing thereto the corrections in training and elevation to be applied to the gun elevating and training means.

10. In a fire control system, sighting means, a predictor, gun elevating and training means, a pair of swash-plate hydraulic motors each having an output to the sighting means for adjusting the sighting means for training and elevation, a pump common to said motors, a power unit driving said pump, a pair of manually controlled valves for regulating the supply of pressure fiuid to said motors, connections from said valves to said predictor for transmitting to the predictor movements proportioned to the rate of change of the valve positions, means transmitting the training and elevating adjustments of the sighting means to said predictor, a power amplifier hunter follow-up system for driving the gun elevating and training means, outputs from the preamaasd elevation-to be applied to "the-"gun elevating and" training'means, and-means for' determining lag correction in the hunter follow-up system consist'ing of a member arranged '-to move-with the serisitive'input to said system,a second member arranged to move with the-power output from said system and a connecting mechanism between said members, saidconnecting'mechanism being so constructed and arranged that when said members run in the same direction at the same speed the-connecting mechanismhas no output while a clifirence in movement of said members producesa corresponding" output from said conneoting mechanism. whereby 'the lag of said gear is determined.

11. Ina fire control system, an'observing sight, a predictor, gun operating mechanism, a first hydraulic swash-plate motor having an output to saids'ight for adjusting athe' -sight in training, a seco'nd hydraulic swash-plate 'motor having an output :for:adjusting the sight in elevation, means transmitting. said training and elevating adjustmerits of the sight to' the predictor, a hydraulic power. amplifierhunterj follow-up system for driving the gun'zoperating mechanism, outputs from theipredictor to'said'ipow'en amplifier system for introducingtheretoiitheicorrections in training and elevation :to be applied: to :the 'gun operating mechanism, said hydraulic power amplifier hunter follmv-up.zsystemiembodying a. pair of swashplate nhydra ulic motors,'.- power' driven pump mean'sto pump hydraulic fluid to said first, second :iand:.pair: .of swash-plate hydraulic" motors,

selectively adjustable'meanszoontrolling the flow of hydraulicrpressure fluid-iito'said first and secondeswash-plate; rnotors,xmeans transmitting to the predictor movements f-proportional to the rate of changeof *th'e elevat'ing and training-M justments derived" from-"the adjustment of said selectively adjustable means? a valve "controlling the flow of hydraulic"pressure"fiui d to"each-0f said *pair' of' swash-"plate"motorsj -an epicyclic gear connecting the input s'haft" pair of swash-plate*motorsto'-oneof"the output fronr the" predictor; and'a cam for' actuating each" of said valves 'driven 'by' -the*-associated -=epicycli gear;- said eams beingso' construoted" that the as sociated -va1ves-=areadj usted away froma zer setting in 'accordancewith the difference-in tn relative positions of said outputs-from the pre dictbr=and the input sha f-ts Ofsaidpairof swash-'- plate motors.

THOMAS FREDERTGK CHARKEI goldby'; Deceased:

REE-ERENGES eI-TED The following referenlces.arehofcrecord i'nithe file of this patent:

UNITED' STATES' PA'I'ENTS"f 

